Machine for cutting or generating the teeth of wheels



May 13, 1930. s. SUNDERLAND MACHINE, FOR CUTTING OR GENERATING THE TEETH- OF WHEELS Filed Nov. 29, 1927 Patented May 13, 1930 urr STATES SAM SUNDERLAND, F KEIG-HLEY, ENGLAND MACHINE FOR CUTTING 0R GENERATING THE TEETH OF WHEELS Application filed November 29, 1927, Serial No. 236,458, and in Great Britain December 28; 1926.

This invention relates to the type or class of machines for cutting or generating the teeth of wheels in wl ich the blank which is being cut revolves continuously about its axis during the time that the reciprocating cutter efl ects the cutting operations by moving over the blank, the feed for the cutting of the teeth being carried out by the cutter being moved tangentially over said blank in such manner that when the teeth of the cutter have moved sulliciently far over the tangent that one complete tooth has been out said cutter is then reversed in its advancing movement and brought back to recommence its cutting operations to produce the next tooth while as is stated the blank is continuously revolving in manner well known.

In this type of machine it is usual to feed the cutter in the tangential direction described by the employment of a worm or screw which is actuated automatically through change speed gearing in order that the space which it moves through over the tangent of the blank is kept equal to the circumterential motion or said blank which is moving simultaneously therewith and by the cutie thus being fed tangentially thereto (commencing below the axis of the blank and travelling over the tangent of said blank) the tooth is generated by the advancing of said cutter through a space equal to the pitch of one tooth from the other and after completing said cutting actions the cutter is again readjusted in its commencing position to be again caused to advance tangentially over the periphery of the blank as is well,

known. 7

I have found under certain conditions and to produce teeth of the desired shape and with the greatestaccuracy as to dimensions, the'actions of the change speed gearing and the Worm or screw which operates the carri age to feed the cutters as described, are not so accurate as is sometimes desired. To obviate this defect by the employment of means which will ellect the cutting or generating of the teeth of wheels with the greatest accuracy and regularity is the. object of my pr sent invention, and to attain this object I make use of sliding inclines instead o1 the screws for effecting the tangential generating movements of the cutter as above explained. These inclines I proportion and arrange to be operated so that the gradual advancing movement of the cutter is carried out without any reverse movement of the blank but with a reverse movement of the cutter when each single tooth has been cut until the whole series of teeth are separately generated.

In order that my said invention may be readily understood, I have hereunto appended a sheet of drawings illustrative thereof, to which by figures and; letters, reference is made in the following description Fig. l is a side elevation partly in section showing the type of machine to which my invention relates with my improved parts applied thereto. a

Fig. 2 is an elevation of certain of the parts snown byFig. 1 as seen looking from right to of said figure.

Figs. 3 and a show one or" the members 0]": my improved devices in detail;

and 6 illustrate another member of my improveddevices hereinafter explained.

In this type of machine as is well known the usual vertical screw which efi -ects the rising and falling movements of thesliding hearings 2 over the framework 3 in order to teed the cutters 4t tangentially to the blank 5 which is being cut, is usually operated by bevel deriving their mot-ion from a horizontal shaft 13 in the machine a t-the outer end 1" which change speed gearing is mounted in order that the amount of motion transmitted ver tically to the cutters l may be adjusted or regulated according to said alterations of the speed ge ring.

Instead of using the screw or worm described and the bevel gearing which operates same I now make use of a sliding incline. 6 which I secure to sliding block 7 the lower surface a of which In perfectly straight and even and is arranged to slide over an appropriate prepared bed plate or base piece 8 so that in its sliding actions the inclined surface Z) of the member 6 will raise the sliding member 2 of the machine, and therefore the cutters a, the desiredspace during the cutting operations.

This inclined surface I) I form of a considerable length so that it has to travel through a considerable space over its base 8 to transmit comparatively little motion to the sliding member 2. As for example I may have the inclined surface I) say twelve inches long and this I arrange to move through the full twelve inches of space while the inclination of its surface I) might only transmit one inch of vertical motion to the sliding bearings 2 and therefore to the cutters 4 when said one inch equals the pitch of the teeth that are being cut. That is to say, when the pitch of the teeth is one inch then the motion ansmitted to the slide 2 would be vertically through one inch of space while the inclined surface Z) to accomplish this would have moved the full twelve inches by which arrangement greater accuracy is secured in the feeding of the cutters 4 to the blank 5 inasmuch as by having an incline b considerably greater than the space through which the cutter 4: is desired to be carried irregularities are reduced to a min imum.

According to one arrangement instead of having the usual change speed gearing wheels I preferably keep said wheels of given proportions to carry out the horizontal motions of the incline b and instead of altering the said change speed wheels to carry said incline Z) through any less space than its full movement to perform the feeding actions to a less degree, I prefer to make use of separate inclined pieces 6 for each pitch of teeth that has to be cut and I keep the travelling of said incline b constant while the inclination of said surface I) will vary according to the greater or less pitch of teeth that has to be generated.

In cases where the great accuracy hereinbefore referred to is not required, it is obvious that instead of moving the inclined piece 6 through the whole of its path when cutting gearing of a rougher or less accurate kind, I may make use of change speed gearing for carrying out the movement of the incline 6 through aless or greater space as desired. Or again I may mount the inclined member 6 upon a sliding member 7 so that its inclined surface I) may be adjusted by causing the member 6 to pivotally move upon a stud 9 which is fixed to the sliding member 7, while the quadrant slot 6 enables me to secure the inclined member 6 by a bolt 6" i any raised position in which I may have adjusted same.

To secure an absolutely solid adjustn'ient of this adjustable member 6 in its proper position, I mount a detachable bush 10 upon a pin or stud 11 which is fixed to or formed integrally with the sliding member 7 thus the lower edge of the member 6 as shown at Fig. 2 cngaginga different bush 10 will support said member 6 in a higher or lower position where it may be further secured by the bolt 6 as above described, by which means the varied pitches of teeth may be regulated with the greatest accuracy without altering any of the change speed gearing as heretofore explained.

The sliding member 7 upon which the incline piece 6 is fixed has rack teeth '4'" formed upon its upper edge and these are arranged to gear with a pinion 12 which is fired upon the shaft 13 so that motion is transmitted at the desired speed through the desired space by said shaft 13 through the pinion 12 to the rack 7 and therefore to the sliding member 7 and its incline 6.

Arranged to span and slide upon the incline (3 an engaging bracket 14 whicl caused to rise and fall as the incline b is forced forward and backward through same as will be unden stood, and this sliding bracket 14 is fixed by a pin 15 taking through its hub part ltt so as to enter and take within the sliding member 2 by which arrangement the rising and falling movements of the bracket 1 f produced or efiected by the actions of the incline 6 are transmitted to the slide 2 and therefore to the cutter 4.

When it is found. that wheels having teeth of what are known as bastard pitches such for example as a pitch that is .728 I may use an incline which will give me the .75" movement when moved through its full length and in connection with such incline I then have the change wheels upon the shaft 18 to reduce that movement so as to give .723 of a rise and these variations may be made as required for the Varied pitches desired.

Such being the nature and object of my said invention what I claim is 1. In a cutter machine of the class described, a movable cutter support, a member extending transversely of the machine, an arm pivoted to said member and having an inclined upper surface, a bracket slidably engaging said inclined surface and connected to said support, whereby upon the actuation of said member a reciprocating movement is imparted to said cutter support, and means for moving said member transversely of the machine.

2. In a cutter machine of the class described, a movable cutter support, a member extendin g transversely of the machine, an arm pivoted to said member and having an. in clined upper surface, a bracket slidably engaging said inclined surface and connected to said support, means for varying the inclination of said arm and maintaining the same in a predetermined fixed position, whereby upon the actuation of said member, a reciprocating movement is imparted to said cutter support, and means for moving said member transversely of the machine.

SAM SUNDERLAND. 

